Comparative study of four Mystus species (Bagridae, Siluriformes) from Thailand: insights into their karyotypic diversity

Karyotypes of four catfishes of the genus Scopoli, 1777 (family Bagridae), Fowler, 1937, Roberts, 1992, (Bleeker, 1846) and (Bleeker, 1851), were analysed by conventional and Ag-NOR banding as well as fluorescence in situ hybridization (FISH) techniques. Microsatellite d(GC) , d(CAA) , d(CAT) and d(GAA) repeat probes were applied in FISH. The obtained data revealed that the four studied species have different chromosome complements. The diploid chromosome numbers (2n) and the fundamental numbers (NF) range between 52 and 102, 54 and 104, 56 and 98, or 58 and 108 in , , or , respectively. Karyotype formulae of , , and are 24m+26sm+4a, 26m+24sm+2a, 24m+18sm+14a and 30m+22sm+6a, respectively. A single pair of NORs was identified adjacent to the telomeres of the short arm of chromosome pairs 3 (metacentric) in , 20 (submetacentric) in , 15 (submetacentric) in , and 5 (metacentric) in . The d(GC) , d(CAA) , d(CAT) and d(GAA) repeats were abundantly distributed in species-specific patterns. Overall, we present a comparison of cytogenetic and molecular cytogenetic patterns of four species from genus providing insights into their karyotype diversity in the genus.